The background of the invention will be discussed in two parts:
1. Field of the Invention
This invention relates to record engraving apparatus, and more particularly to an improvement of a record engraving apparatus for forming lead-in and lead-out tracks on a master record, or master lacquer.
2. Description of the Prior Art
Records having generally spiral grooves for tracking by a phonograph needle have been used in various devices for electronic or mechanical reproduction of sound.
In various toys, a phonograph record is used having interleaved tracks, that is, each track includes a separate lead-in groove at the periphery of the record disk, in contrast to conventional phonograph records, in which essentially a single spiral track is produced across the surface of the disk, with each recording separated from the next by a separate lead-in track of a different pitch coextensive with the lead-out track of the previous recording. In either event such record disks are formed by the use of suitable recording apparatus.
Each groove of the disk in such toys is recorded with a different song or phrase. In forming the master disks for such records, in the past, the individual interleaved spiral grooves of the master lacquer have been cut using conventional techniques. Thereafter, the lead-in and lead-out grooves in the master lacquers have been cut manually, and require precision arrangement to insure proper operation of the toy or device in which used.
A device for recording sound is shown and described in U.S. Pat. No. 1,649,847, issued Nov. 22, 1927, to Nightinghall. This apparatus includes a heated recording stylus which is maintained in contact with the record surface to generate a helical groove therein.
Another apparatus is shown and described in U.S. Pat. No. 2,595,795, entitled "Spiral and Eccentric Groove Cutter for Phonograph Records and the Like", issued May 6, 1952, to Kovach. This apparatus is adapted for coaxial mounting with the record in which the grooves are to be cut.
Another apparatus is shown and described in U.S. Pat. No. 3,420,967, entitled "Disc Recording and Reproducing System", issued July 1, 1963 to Goldmark. This system is intended for recording information upon a record disc in less time than the playback time. This system includes electronic filter means to assist in the increased speed of recording.
Another apparatus is shown and described in U.S. Pat. No. 3,837,656, entitled "Chip Removal in the Mastering of Fine-Grooved Discs", issued Sept. 24, 1974, to Pradervand. This apparatus provides a source of heated air and a chip collector adjacent thereto for removing chips generated during cutting. Another apparatus is shown and described in U.S. Pat. No. 3,528,665, entitled "Method and Apparatus for Cutting a Groove in the Surface of an Original Recording Disc", issued Oct. 15, 1974 to Redlich. This apparatus is directed to means using a cutting stylus in such a way to completely remove the original surface of the disk.
Another apparatus is shown and described in U.S. Pat. No. 3,842,194, entitled "Information Records and Recording/Playback Systems Therefor", issued Oct. 15, 1974, to Clemens, and discloses a storage medium comprising a metallized base material having a dielectric coating thereon for use with a capacitance responsive stylus system.
Another apparatus is shown and described in U.S. Pat. No. 3,909,517, entitled "Disc Records with Groove Bottom Depth Variations", issued Sept. 30, 1975, to Clemens, this patent disclosing an improvement of the preceding Clemens patent. Another apparatus is shown and described in U.S. Pat. No. 4,248,438, entitled "Mechanical Record Cutting Method", issued Feb. 3, 1981, to Knothe, et al, the apparatus providing a stylus for electromechanically cutting a groove in a copper coated metal surface of a master disk with a cutting angle of the stylus of between 10 to 20 degrees. This apparatus is adapted for coaxial mounting with the record in which the grooves are to be cut.
It is an object of the present invention to provide a new and improved record engraving apparatus.
It is another object of the present invention to provide a new and improved computer numerically controlled apparatus for engraving a master disc or master lacquer.
It is a further object of the present invention to provide a new and improved record engraving apparatus for enabling precise cutting of lead-in and/or lead-out grooves on a master lacquer having interleaved spiral record grooves.